A transistor array panel includes switching elements provided in intersecting portions between gate and data lines, and display electrodes connected to the switching elements. A conductive film pattern is provided to be electrically insulated from the gate and data lines, and display electrodes, and to be overlapped on the display electrodes, thereby forming a storage capacitance between each of the display electrodes and the conductive film pattern. A protection circuit is electrically connected to the gate and data lines, and disposed in an outer peripheral portion of a display region in which the switching elements and the display electrodes are formed on the one side of the substrate. A common line is insulated from the protection circuit, connected to the conductive film pattern, and provided to be insulated from the protection circuit and to be at least partially overlapped on the protection circuit, in the outer peripheral portion of the display region.